the head of the tsa will visit his family in los angeles today. it's the first time a tsa officer has been killed on duty in the agency's 12 years. who is the shooter? why did he snap? why was he targeting the tsa? we look into the gun man's background. >> reporter: in the small town of pennsville, new jersey, paul anthony ciancia's family got a disturbing text. it was troubling enough that allen cumming was called to the house. he said the text they received suggested the 23-year-old might kill himself. >> our procedure is if someone is concerned about a family member, we call that local police department and do a well-being check and that's basically what we did. it came back he wasn't home. >> l.a.p.d. officers went to his apartment and talked to his roommates. they said the 23-year-old just left, but seemed to be fine. >> he was a nice guy, a little loner, introverted, but nothing that i would ever, ever expect him to do something like this. >> about the same time chaos was erupting at lax. at the had no idea that a gunman, later identified as